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This diagram shows the structure of the Sun's interior. Two major regions inside the Sun, the convective zone and the radiative zone, are named for the way heat travels through them.
Click on image for full size NASA

Temperature is a familiar idea that is a big part of thermal physics.
Three scales for measuring temperature are in common use: Fahrenheit, Celsius
(or Centigrade), and Kelvin. The temperature of a gas is really a measure
of the average speed with which molecules or atoms are hurtling about. We infer
the temperatures of stars from their colors; hot stars are blue while cooler
ones are red.

In our everyday speech, heat and temperature mean the same thing. In the
language of thermal physics, the two terms have different
meanings. Heat is the amount of thermal energy stored in an
object.
Heat can flow from one object to another, transferring energy in the process.
The flow of heat can melt ice or warm the surfaces of planets near a star. The Laws of Thermodynamics
describe the fundamental physics of heat and its flows.

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